patch 8.2.3608: users who type "q:" instead of ":q" are confused

Problem:    Users who type "q:" instead of ":q" are confused.
Solution:   Add an autocmd to give a message that explains this is the
            command-line window. (Egor Zvorykin, closes #9146)
diff --git a/src/testdir/test_autocmd.vim b/src/testdir/test_autocmd.vim
index 9eb718f..045320e 100644
--- a/src/testdir/test_autocmd.vim
+++ b/src/testdir/test_autocmd.vim
Binary files differ
diff --git a/src/testdir/test_cmdline.vim b/src/testdir/test_cmdline.vim
index 87ae6fa..295e59d 100644
--- a/src/testdir/test_cmdline.vim
+++ b/src/testdir/test_cmdline.vim
@@ -1255,6 +1255,7 @@
   CheckScreendump
 
   let lines =<< trim [SCRIPT]
+    augroup vimHints | au! | augroup END
     call setline(1, range(30))
     2split
   [SCRIPT]
diff --git a/src/version.c b/src/version.c
index e0bc5c1..e5146bc 100644
--- a/src/version.c
+++ b/src/version.c
@@ -758,6 +758,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    3608,
+/**/
     3607,
 /**/
     3606,